A computer network is a collection of computers and other hardware interconnected by communication channels that allow sharing of resources and information. Communication protocols define the rules and data formats for exchanging information in a computer network.
A distributed database is a computing entity that holds data across a number of computers. These computers can be interlinked with computer networking links, allowing the computers to communicate with each other and coordinate the tasks associated with the database. In some distributed databases, the constituent computers can be organized into computing clusters and assigned to respective roles in the distributed database. These roles may, for example, describe some of the permissions and activities of the cluster in the distributed database.